Chipper head and blade



R. M. NOEL Dec. 5, 1967 CHIPPER HEAD AND BLADE Filed Oct. 13 1965Roberi" M.N0e1

INVENTOR BY United States Patent 3,356,114 CHIPPER HEAD AND BLADE RobertM. Noel, Sherwood, 0reg., assignor to Key Machinery Designers, Inc.,Portland, 0reg., a corporation of Oregon Filed Oct. 13, 1965, Ser. No.495,465 4 Claims. (Cl. 144172) ABSTRACT OF THE DISCLOSURE A rotary bodymember has a longitudinal recess extending parallel to its rotationalaxis and provided with an arcuate blade-supporting trailing surface. Akeeper is mounted removably in the recess and supports a removable gibhaving an arcuate surface spaced from and facing the arcuateblade-supporting surface of the recess, forming an arcuateblade-receiving space in which is received a chipper blade having acorrespondingly arcuate cross section. The cutting edge of the bladedefines the apex of an angle of at least 50 formed by the intersectionof a line extending through the rotational axis of the body and a lineextending tangential to the leading surface of the blade in the trailingdirection of rotation of the body.

This invention relates to wood chippers, and more particularly to achipper head and blade which represents an improvement over the chipperhead and blade disclosed in US. Patent No. 2,899,992.

It is the principal object of the present invention to provide a chipperhead and blade which accommodates periodic sharpening of the blade whilemaintaining constant radial length of rotation of the cutting edge ofthe blade and constant operating angle of the blade.

Another important object of this invention is the provision of a chipperhead and blade assembly which is of simplified construction foreconomical manufacture, which aifords adjustment with speed and facilityand which is of rugged construction for long service life.

A further important object of the present invention is the provision ofa one piece chipper blade which extends the full length of thesupporting head.

The foregoing and other objects and advantages of this invention willappear from the following detailed descrip tion, taken in connectionwith the accompanying drawing in which:

FIG. 1 is a plan view of a chipper head and blade assembly embodying thefeatures of the present invention;

FIG. 2 is an end elevation viewed from the right in FIG. 1-,

FIG. 3 is a fragmentary sectional view taken on the line 3--3 in FIG. 1;and

FIG. 4 is a fragmentary sectional view taken on the line 44 in FIG. I.

In the preferred embodiment illustrated, the chipper head comprises agenerally cylindrical body having an axial bore for mounting on a powerdriven shaft 12 for rotation therewith. In the embodiment illustrated,an inner portion of the bore is tapered to larger diameter at the innerend of the body, for mounting on a correspondingly tapered portion ofthe driven shaft. The outer portion of the shaft is threaded forreception of the nut 14, by which the body is secured frictionally tothe rotary shaft.

The chipper head body is contoured to provide for the mounting of atleast one chipper blade. In the preferred embodiment illustrated,provision is made for the mounting of two blades arranged symmetricallywith respect to the axis of the body. It is to be understood, of course,that the head may accommodate more than two symmetrically arrangedblades, as desired.

The support of each blade is achieved by removing a 3,356,114 PatentedDec. 5, 1967 ice longitudinal portion of the body to provide alongitudinal recess adapted to accommodate the mounting of the elongatedkeeper 16 and gib 18. The rearward side of the keeper is provided with arearwardly projecting key 20 adapted for sliding engagement in thekeyway 22 formed in the body. The keeper is provided with a plurality oflongitudinally spaced openings 24 adapted to receive the securing bolts26 which are threaded into tapped openings provided in the body.

The elongated gib 18 is secured to the surface of the keeper trailingthe direction of rotation of the head, by means of the attaching bolts28 which extend through openings 30 in the keeper and are threaded intapped openings in the gib.

The trailing surface 18' of the gib is arcuate in shape, and is spacedfrom the correspondingly arcuate leading surface 32 of the recess facingthe direction of rotation of the head. The arcuate space thus providedreceives the correspondingly arcuate elongated chipper blade 34 which issecured firmly therein by tightening of the bolts 26 to draw the gibinto firm clamping contact with the blade.

In addition to the clamping pressure provided by the gib, the blade ismaintained in proper position of adjustment, against the opposingcentrifugal force created by rotation of the head, by arranging thearcuate surface 32 such that a radial line drawn from the axis ofrotation of the head through the cutting edge of the blade forms with aline drawn tangential to the surface 32 at the periphery of the head anincluded acute angle B.

In accordance with the disclosure in the aforementioned Patent No.2,899,992, the blade is positioned on the chipper head body in suchmanner that a radial line drawn from the axis of rotation of the head tothe cutting edge of the blade forms with a line drawn from the cuttingedge of the blade tangential to the leading surface of the blade in thetrailing direction thereof, an included angle A not substantially lessthan 50. It is explained in the aforementioned patent that this is animportant requirement for the production of wood pulp chips ofacceptable quality.

As the cutting edge of the blade becomes worn and requires resharpening,the keeper and gib assembly is loosened to allow the blade to be movedoutwardly along the arcuate confining space to expose a greater portionof the cutting end of the blade. The keeper and gib assembly then isretightened to secure the blade. After each blade has thus been adjustedoutward, the head assembly is rotated and the cutting edges of theblades are sharpened, and jointed if desired.

As each blade is moved outwardly for successive resharpening, it may bedesirable to fill the space formed between the inner edge of the bladeand the associated keeper. This may be accomplished by the insertion ofshims 36, as illustrated, or by any other suitable means such as babbit,etc.

It will be apparent that the use of the arcuate blade describedhereinbcfore provides the advantage of accommodating a substantialnumber of resharpenings while maintaining constant the radial distanceof rotation and the included angle A throughout the useful life of theblade. The one piece blade construction simplifies considerably theconstruction of the head and correspondingly minimizes the cost of thelatter as well as the blade, while additionally affording resharpeningand other maintenance with speed and facility, thereby minimizing downtime.

It will be apparent to those skilled in the art that various changes maybe made in the number, size and arrangement of parts, as well as otherstructural details described hereinbefore, without departing from thespirit of this invention and the scope of the appended claims.

Having now described my invention and the manner in which it may beused, What I claim as new and desire to secure by Letters Patent is:

l. A rotary chipper head assembly, comprising (a) a body member adaptedto be mounted for rotation on its longitudinal axis,

(b) the body member having a longitudinal recess extending substantiallyparallel to its rotational axis, the trailing side of the recess havingan arcuate bladesupporting surface extending inward from the outerperiphery of the body member,

(c) a keeper member mounted removably in the recess of the body memberand a gib member mounted removably on the keeper member and having anarcuate surface spaced from and facing the arcuate bladesupportingsurface of the recess, forming an arcuate blade-receiving spacetherebetween, and

(d) a chipper blade having an arcuate cross sectional shape dimensionedfor reception in said blade-receiving space.

2. The assembly of claim 1 wherein the body member has a longitudinalkey groove communicating with the recess, and the keeper member has alongitudinal key portion adapted for reception in said key groove.

3. A rotary chipper head assembly, comprising (a) a body member adaptedto be mounted for rotation on its longitudinal axis,

(b) the body member having a longitudinal recess extending substantiallyparallel to its rotational axis, the trailing side of the recess havingan arcuate bladesupporting surface extending inward from the outerperiphery of the body member,

(c) blade-securing means mounted removably in the recess of the bodymember and having an arcuate surface spaced from and facing the arcuatebladesupporting surface of the recess, forming an arcuateblade-receiving space therebetween, and

(cl) a chipper blade having an arcuate cross sectional shape dimensionedfor reception in said blade-receiving space,

(c) said trailing arcuate surface of the head being arranged such that aradial line from the axis of rotation of the head through the cuttingedge of the blade forms with a line tangent to the said arcuate surfaceat the periphery of the head an included acute angle.

4. A rotary chipper head assembly, comprising (a) a body member adaptedto be mounted for rotation on its longtiudinal axis,

(b) the body member having a longitudinal recess extending substantiallyparallel to its rotational axis, the trailing side of the recess havingan arcuate bladesupporting surface extending inward from the outerperiphery of the body member,

(c) the body member having a longitudinal key groove communicating withthe recess,

(d) a keeper member adapted to be mounted removably in the recess of thebody member,

(e) the keeper member having a longitudinal key portion adapted forreception in the key groove,

(f) a gib member mounted removably on the keeper member and having anarcuate surface spaced from and facing the arcuate blade-supportingsurface of the recess forming an arcuate blade-receiving spacetherebetwccn, and

(g) an elongated chipper blade having an arcuate cross sectional shapedimensioned for reception in said blade-receiving space,

(h) the blade being mounted on the body member with its cutting edgedefining the apex of an angle of at least 50 formed by the intersectionof a line extending through the rotational axis of the body member and aline extending tangential to the leading surface of the blade in thetrailing direction of rotation of the body member.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 3/1959 France.

WILLIAM W. DYER, JR., Prr'lmzry Examiner. \N. D. BRAY, AssistantExaminer.

1. A ROTARY CHIPPER HEAD ASSEMBLY, COMPRISING (A) A BODY MEMBER ADAPTEDTO BE MOUNTED FOR ROTATION ON ITS LONGITUDINAL AXIS, (B) THE BODY MEMBERHAVING A LONGITUDINAL RECESS EXTENDING SUBSTANTIALLY PARALLEL TO ITSROTATIONAL AXIS, THE TRAILING SIDE OF THE RECESS HAVING AN ARCUATEBLADESUPPORTING SURFACE EXTENDING INWARD FROM THE OUTER PERIPHERY OF THEBODY MEMBER, (C) A KEEPER MEMBER MOUNTED REMOVABLY IN THE RECESS OF THEBODY MEMBER AND A GIB MEMBER MOUNTED REMOVABLY ON THE KEEPER MEMBER ANDHAVING AN ARCUATE SURFACE SPACED FROM AND FACING THE ARCUATEBLADESUPPORTING SURFACE OF THE RECESS, FORMING AN ARCUATEBLADE-RECEIVING SPACE THEREBETWEEN, AND (D) A CHIPPER BLADE HAVING ANARCUATE CROSS SECTIONAL SHAPE DIMENSIONED FOR RECEPTION IN SAIDBLADE-RECEIVING SPACE.